Hello,
To handle these cases we already have 2 possibilities:
As a Scrum Master, I can move a task with a responsible without “take” the responsibility. In fact you only update as the responsible would be. I can also update the remaining time.
As a Scrum Master ,with iceScrum Pro, I can start the task board feature which is very useful during the daily meeting. I would be able to take, release and update tasks as any user in the team without login / logout. More information here: https://www.icescrum.com/documentation/task-board/
Another possibility would be “assignment” but it’s not part of our Scrum / Agile vision.
Cheers;